Conventionally, as, for example, ball joints used in automobile suspension devices, steering devices, or the like, there has been known one including a socket in an approximately cylindrical shape with a bottom having an inner chamber provided with an opening portion and a bottom surface portion, a ball seat as being a bearing seat housed in the inner chamber of this socket and having an opening communicated with the opening portion, a cushion seat as being an elastic member interposed between this ball seat and the inner chamber of the socket, and a ball stud having a ball portion held so as to be slidable on a sliding surface in the ball seat and a stud portion inserted through the opening and the opening portion. And, for this ball joint, formed at an end portion on a side opposite to the opening of the bearing seat is a load receiving surface portion opposed to the bottom surface portion of the inner chamber of the socket, and when a compressive load in the axial direction equal to or greater than a predetermined value is applied to the ball stud, the load receiving surface portion of the bearing seat comes into contact with the bottom surface portion of the inner chamber of the housing, whereby the load is received by the bearing seat so as to prevent settling of the elastic member in the axial direction (see, for example, Japanese Examined Patent Publication No. 7-30781 (Pages 2-3, FIG. 1)).